Tunable domain-wall skyrmion Hall effect driven by a current and a magnetic field

An extended domain wall (DW) in the presence of the Dzyaloshinskii-Moriya interaction can harbor a nontrivial spin texture inside it, which is called the DW skyrmion due to its topological equivalence to skyrmions in chiral magnets. In this study we develop a theory for the dynamics of the DW skyrmion and demonstrate, using micromagnetic simulations, that the DW skyrmion exhibits the skyrmion Hall effect akin to conventional skyrmions. Notably, we find that, distinct from the conventional skyrmion Hall effect induced by the current, the DW skyrmion Hall effect can be induced not only by a current, but also by a uniform magnetic field. We also find that, by exploiting the fact that the spin-transfer torque and magnetic field result in the skyrmion Hall effect in different directions, it is possible to adjust the net skyrmion Hall angle, including elimination of the skyrmion Hall angle. Our work shows that the DW skyrmion can exhibit topological dynamics that are absent in conventional skyrmions, which leads us to envision that skyrmionics may benefit from further investigations of its properties.